The invention relates to a needle bed for a knitting machine.
Knitting machines have been known, for example, designed as circular knitting machines or as flat-bed knitting machines. While the latter comprise at least one essentially flat needle bed, the needle beds of circular knitting machines are designed as hollow cylinders acting as knitting cylinders or in a ring-shaped manner to represent rib dials. Each needle bed has needle channels into which are set the knitting tools such as, for example, needles or sinkers. During operation, the knitting tools are moved back and forth in the needle bed.
German Patent Document DE 24 16 626 A1 discloses such a needle bed and also teaches to provide the needle bed with grooves extending in a direction transverse to the needle channels and to blow an air/oil mixture through bores into these grooves. The groove walls that delimit the guide channels of the knitting tools may be provided with recesses, so that the lubricant may better spread between the knitting tools and their guide channels.
Considering this arrangement, it is quite difficult to maintain control over the spreading of the lubricant in the needle bed.
German Patent Document DE 1 635 836 A discloses a knitting cylinder as well as a rib dial in a circular knitting machine. Both may be provided with annular grooves that intersect the guide grooves of the knitting tools. Pressurized air may be blown into the cam ring through these annular grooves.
Furthermore, the injection of pressured air into the needle bed has been known from document DD 37 345 A, whereby the pressurized air is to prevent the accumulation of debris in the cam area of the affected knitting machine.
Pressurized air is a process medium that, when used, is connected with considerable operating costs. Therefore, one objective must be to lower the amount of pressurized air required for the operation of a knitting machine.
Furthermore, the accumulation of debris in the needle beds of knitting machines represents a problem that promotes wear and shortens maintenance intervals. Consequently, it must be an objective to avoid the accumulation of debris in the needle carriers of knitting machines.
Also, with increasing operating speeds of knitting machines, the reliability of the lubrication of the knitting tools becomes of importance. Knitting tools that run partially dry result in an increased use of energy and in wear of the knitting tool and of the knitting machine.
Considering this, it is the object of the invention to produce a knitting machine displaying improved air supply.